I do a second ferment with my kombucha which makes it super carbonated. When I bottle my kombucha, I let it sit out at room temp anywhere from 4 days to 2 weeks. It will get very fizzy so be careful when opening this. Ive had kombucha shoot out all over my kitchen. I also add flavorings - herbs and spices - if i desire, before putting down for a second ferment.I do the same with water kefir as well, but only for about 2 to 3 days. It carbonates FAST!

Keeping it in a sealed container will force more of the CO2 to dissolve in the liquid, but this can be dangerous if it's sealed too tightly. I use a large canning jar with a glass bail-top lid and rubber seal for both kombucha and kefir. This type of lid seems to seal just tight enough to keep in most of the carbonation, but doesn't allow the pressure to build up to a dangerous level. Keeping the ferment under some amount of pressure for at least a short period of time is the trick.

Yes, this is partially correct. I bottle it and then set it at room temp for a second ferment with sealed bottles. I do this second ferment anywhere from about 3 to 4 days up to 2 weeks (usually its about a week) for kombucha. I have never done 4 weeks. THat might give a tremendous amount of carbonation. With kefir water ive never had to do more than about 2 days to get it really carbonated. Kefir water gets fizzy fast and then can shoot all over the kitchen when opening. Ive never had a bottle explode on me, but when i first tried this, i did let it ferment in the basement, as i was not familiar with if it could explode or not. I use thick walled glass bottles with a flip top. I have heard of people having exploding bottles though, so do be cautious with this and keep a close eye. I often will check my bottles by opening (outside if you are unsure) and seeing how fizzy it gets. It also greatly depends on the climate you live in and the temp. I live in Maine where its usaully pretty mild. I also brew - right now medicinal herbal beers - and am reading about people having explosions with those. One person talked about when a storm front came in and the barometric pressure dropped having many of his beer bottles that were fermenting explode on him.

Do you find that the mason jars hold sufficient carbonation? Does yours come out bubbley (like soda)? While ive never had any bottles explode and choose thick walled bottles for doing this second ferment, it has been a concern of mine. Ive tried screw top bottles, like from mineral waters, and found them not holding enough carbonation.

I never let mine get quite to a "soda-pop" level of carbonation, but it does get pretty fizzy. Then again I'm not that big on carbonation. I actually prefer my beer with much less carbonation than you find in commercial brews. I honestly think the high levels of carbonation in (American) commercial beer have much to do with our Pepsi/Coke culture, and often overwhelm the flavor of the beverage.

The jars I use for kombucha and kefir have wide-mouth bail tops with a rubber gasket. They seem to expel enough excess pressure that there wouldn't be a danger of any exploding. But when I make kombucha, I don't make so much that I could really bottle and store it away. Your bail-top bottles sound like a good choice. I've also noticed that metal screw-down caps (like on mineral water) don't seal down as well after they been used once or twice. I suspect the caps deform after they've been unsealed the first time.

Thanks Tim. I agree with your thought on our predisposed assumptions of what carbonation SHOULD be like. Some schools of thought (ive studied tcm and ayurveda) feel that carbonation inhibits digestion and should be avoided. Some carbonation makes it tastier to me.

I refrigerated my bottled kombucha before learning that if we wanted it fizzy we should keep it room temp. I have been disappointed that when I think we are doing a second fermentation for carbonation, it is never fizzy when I open it right out of the fridge.(except for one time when I added strawberry puree and it was FABULOUS!). I am wondering if I take a bottle out of the refrigerator for a day or so before drinking it, would it become carbonated? If I try it myself and figure it out, I'll post my own answer.

As you've noticed with the strawberry puree added, the fizzy stays. This is caused by the residual yeast fementing the sugards in the puree in an anaerobic environment causing a higher concetration of dissolved CO2 in the solution.

Durring the bottling process of my beer batches, I always add a small amount of sweet wort or white sugar to the bottle to get good bottle conditioning. This applies to kombucha too.

My best success is making a grind of chrystalezed ginger and adding about 1/2tsp to each bottle.

I get a good ginger bite from it and a very nice fizz after about 4-7 days in the bottle that stands up to refigeration fairly well.

Not quite as strongly fizzy as soda pop but enough to taste the fiz and have some un.